Radar apparatus and radar signal processing method

Abstract

A radar apparatus includes: a first module; a second module; and a cable that connects the first module to the second module, in which the first module includes: a signal processing circuit that outputs a plurality of beat signals respectively for a plurality of reception antennas, and a control circuit that starts the signal processing circuit in accordance with a start command received from the second module via the cable, and the second module includes: a detection circuit that detects an object based on the plurality of beat signals received from the first module via the cable, and a command circuit that transmits the start command to the first module.

1 . A radar apparatus, comprising:
 a first module;   a second module; and   a cable that connects the first module to the second module, wherein   the first module includes:
 a signal processing circuit which, in operation, outputs a plurality of beat signals respectively for a plurality of reception antennas, and 
 a control circuit which, in operation, outputs a control command to the signal processing circuit in accordance with a start trigger command received from the second module via the cable, the control command being used for starting the signal processing circuit, and 
   the second module includes:
 a detection circuit which, in operation, detects an object based on the plurality of beat signals received from the first module via the cable, and 
 a command circuit which, in operation, transmits the start trigger command to the first module. 
   
     
     
         2 . The radar apparatus according to  claim 1 , wherein:
 the plurality of reception antennas include a plurality of first reception antennas and a plurality of second reception antennas;   the signal processing circuit includes a first signal processing circuit and a second signal processing circuit, the first signal processing circuit outputting first beat signals respectively for the plurality of first reception antennas, the second signal processing circuit outputting second beat signals respectively for the plurality of second reception antennas, the first beat signals being parallel to one another, the second beat signals being parallel to one another;   the first module includes a first conversion circuit and a second conversion circuit, the first conversion circuit converting the first beat signals being parallel to one another into first serial signals and outputting the first serial signals to the cable, the second conversion circuit converting the second beat signals being parallel to one another into second serial signals and outputting the second serial signals to the cable; and   the second module includes a third conversion circuit that restores the first serial signals received via the cable into the first beat signals being parallel to one another, restores the second serial signals received via the cable into the second beat signals being parallel to one another, and outputs to the detection circuit the first beat signals restored and the second beat signals restored.   
     
     
         3 . The radar apparatus according to  claim 1 , wherein:
 the plurality of reception antennas include a plurality of first reception antennas and a plurality of second reception antennas;   the signal processing circuit includes a first signal processing circuit and a second signal processing circuit, the first signal processing circuit outputting first beat signals respectively for the plurality of first reception antennas, the second signal processing circuit outputting second beat signals respectively for the plurality of second reception antennas, the first beat signals being parallel to one another, the second beat signals being parallel to one another;   the first module includes a first conversion circuit and a second conversion circuit, the first conversion circuit converting the first beat signals being parallel to one another into first serial signals and outputting the first serial signals to the cable, the second conversion circuit converting the second beat signals being parallel to one another into second serial signals and outputting the second serial signals to the cable; and   the second module includes a third conversion circuit that restores the first serial signals received via the cable into the first beat signals being parallel to one another, restores the second serial signals received via the cable into the second beat signals being parallel to one another, and multiplexes in a time-division manner the first beat signals restored and the second beat signals restored, to output the first beat signals and the second beat signals to the detection circuit.   
     
     
         4 . The radar apparatus according to  claim 2 , wherein
 when receiving a stop command from the command circuit via the cable, the control circuit stops an operation of the first signal processing circuit and the second signal processing circuit within one frame.   
     
     
         5 . The radar apparatus according to  claim 2 , wherein:
 the first module comprises a plurality of the first modules, and the third conversion circuit comprises a plurality of the third conversion circuits; and   the plurality of third conversion circuits are provided to correspond respectively to the plurality of first modules,   wherein each of the plurality of third conversion circuits which, in operation, restores serial signals output from a corresponding first module into first beat signals being parallel to one another and second beat signals being parallel to one another, and multiplexes in a time-division manner the first bear signals restored and the second beat signals restored, to output the first bear signals and the second beat signals to the detection circuit.   
     
     
         6 . The radar apparatus according to  claim 1 , wherein:
 the plurality of reception antennas include a plurality of first reception antennas and a plurality of second reception antennas;   the signal processing circuit includes a first signal processing circuit that outputs first beat signal respectively for the plurality of first reception antennas in parallel, and a second signal processing circuit that outputs a second beat signal respectively for the plurality of second reception antennas in parallel;   the first module includes a first conversion circuit that converts the first beat signals being parallel to one another into first serial signals, converts the second beat signals being parallel to one another into second serial signals, and multiplexes the first serial signals and the second serial signals in a time-division manner to output the first and the second serial signals to the cable; and   the second module includes a second conversion circuit that restores the first serial signals received via the cable into the first beat signals being parallel to one another, restores the second serial signals received via the cable into the second beat signals being parallel to one another, and multiplexes in a time-division manner the first beat signals restored and the second beat signals restored, to output the first beat signals and the second beat signals to the detection circuit.   
     
     
         7 . The radar apparatus according to  claim 6 , wherein:
 the first module includes a compression circuit that compresses the first beat signals being parallel to one another output from the first signal processing circuit and the second beat signals being parallel to one another output from the second signal processing circuit, and outputs the first and the second beat signals to the first conversion circuit; and   the second module includes an expansion circuit that expands the first beat signals being parallel to one another and the second beat signals being parallel to one another output from the second conversion circuit.   
     
     
         8 . The radar apparatus according to  claim 7 , wherein:
 the first module comprises a plurality of the first modules; and   beat signals being parallel to one another from a first module different from the first module are input to the compression circuit.   
     
     
         9 . The radar apparatus according to  claim 6 , further comprising:
 a third conversion circuit that converts a serial signal output from a module different from the first module into a parallel beat signal and outputs the parallel beat signal to the first conversion circuit of the first module.   
     
     
         10 . The radar apparatus according to  claim 1 , further comprising:
 a reproduction circuit between the first module and the second module, the reproduction circuit shaping a waveform of a signal transmitted.   
     
     
         11 . The radar apparatus according to  claim 1 , wherein
 the detection circuit detects a fault in the signal processing circuit based on the plurality of beat signals.   
     
     
         12 . A radar signal processing method, comprising:
 transmitting a start trigger command from a command circuit of a second module to a control circuit of a first module via a cable connecting the first module to the second module;   receiving, by the control circuit of the first module, the start trigger command from the second module;   outputting, in response to the start trigger command, a control command from the control circuit of the first module to a signal processing circuit of the first module, the control command being used for starting the signal processing circuit of the first module;   outputting, from the signal processing circuit started of the first module to a detection circuit of the second module, a plurality of beat signals respectively for a plurality of reception antennas connected to the signal processing circuit of the first module; and   detecting, by the detection circuit of the second module, an object based on the plurality of beat signals received from the first module via the cable.   
     
     
         13 . The radar signal processing method according to  claim 12 , wherein:
 the plurality of beat signals include first beat signals being parallel to one another for a plurality of first reception antennas from among the plurality of reception antennas, and second beat signals being parallel to one another for a plurality of second reception antennas from among the plurality of reception antennas;   the first beat signals being parallel to one another are converted into first serial signals by a first conversion circuit of the first module and are output to the cable;   the second beat signals being parallel to one another are converted into second serial signals by the first conversion circuit of the first module and are output to the cable;   the first serial signals received via the cable are restored into the first beat signals being parallel to one another by a third conversion circuit of the second module;   the second serial signals received via the cable are restored into the second beat signals being parallel to one another by the third conversion circuit of the second module; and   the first beat signals restored and the second beat signals restored are output from the third conversion circuit to the detection circuit.   
     
     
         14 . The radar signal processing method according to  claim 13 , wherein
 the first beat signals restored and the second beat signals restored are further multiplexed in a time-division manner and output from the third conversion circuit to the detection circuit.   
     
     
         15 . The radar signal processing method according to  claim 12 , wherein
 additionally, when the control circuit of the first module receives a stop command from the command circuit of the second module via the cable, an operation of the signal processing circuit of the first module is stopped within one frame by the control circuit of the first module.   
     
     
         16 . The radar signal processing method according to  claim 13 , wherein:
 the first module comprises a plurality of the first modules, and the third conversion circuit comprises a plurality of the third conversion circuits;   the plurality of third conversion circuits are provided to correspond respectively to the plurality of first modules;   serial signals output from each of the plurality of first modules are restored by a corresponding one of the plurality of third conversion circuits into first beat signals being parallel to one another and second beat signals being parallel to one another; and   the first beat signals restored and the second beat signals restored are multiplexed in a time-division manner by each of the plurality of third conversion circuits and output to the detection circuit.   
     
     
         17 . The radar signal processing method according to  claim 14 , wherein
 additionally, the first serial signals and the second serial signals are multiplexed in a time-division manner and output to the cable by the first conversion circuit of the first module.   
     
     
         18 . The radar signal processing method according to  claim 17 , wherein:
 additionally, the first beat signals being parallel to one another and the second beat signals being parallel to one another are compressed by a compression circuit of the first module and output to the first conversion circuit of the first module; and   the first beat signals being parallel to one another and the second beat signals being parallel to one another are expanded by an expansion circuit of the second module, the first and the second beat signals being output from a second conversion circuit of the second module.   
     
     
         19 . The radar signal processing method according to  claim 18 , wherein:
 the first module comprises a plurality of the first modules; and   a parallel beat signal from a different first module is input to the compression circuit of the first module.   
     
     
         20 . The radar signal processing method according to  claim 18 , wherein:
 the first module comprises a plurality of the first modules; and   serial signals output from a first module different from the first module are converted by the third conversion circuit of the second module into the beat signals being parallel to one another, and are output to the first conversion circuit of the first module.